For a gas molecule with 6 degrees of freedom, which one of the following relation between gas constant '$$\mathrm{R}$$' and molar specific heat '$$\mathrm{C}_{\mathrm{v}}$$' is correct?

When the battery across the plates of a charged condenser is disconnected and a dielectric slab is introduced between its plates then the energy stored

The width of central maximum of a diffraction pattern on a single slit does not depend upon

If the amplitude of linear S.H.M. is decreased then